The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

Australia in line to meet Kyoto target

In 2007, then prime minister Kevin Rudd committed Australia to limiting emissions to 108 per cent of 1990 levels on average over the period 2008-2012.

The latest national greenhouse accounts, released by the Environment Department on Thursday, show Australia averaged 105 per cent over the first four years and preliminary figures for 2011/12 showed similar levels to 2010/11.

The report also showed no rise in overall emissions in the year to March, despite growth in gross domestic product.

The main factor behind total emissions flatlining was a drop in emissions from the electricity sector, down 6.1 per cent over the year to March which included eight months of the carbon tax's operation.

However, this was offset by a rise in fugitive emissions (which occur during the production and processing of fossil fuels) and emissions from stationery energy (combustion of fuels by industry).

Environment Minister Greg Hunt said the fact that emissions had not fallen in the first year of the carbon tax showed why it should be abolished.